You absolutely are a Whovian! Whether you’ve seen one episode or you’ve been watching for your entire life, you’re a Whovian. If you’ve only seen New Who, that’s great. If you’ve seen every single episode and the movie, that’s great too.
Being a Whovian isn’t about how many episodes you’ve seen but how much you love the show. If you like Doctor Who and want to be a Whovian then congrats, you are one.